1. Field of Disclosure
The present disclosure of invention relates to a backlight unit and a liquid crystal display (LCD) having the same.
2. Description of Related Technology
Liquid crystal displays (LCDs) have a wide range of applications due to their typical features, namely, lightweight and slim design, low power consumption, full-color, and high resolution. Currently, LCDs are used in computers, notebooks, personal digital assistants (PDAs), telephones, televisions, audio/video equipment, and the like. An LCD device generally displays a desired image on an LCD panel by controlling the amount of transmitted light according to image signals which are used to control a plurality of pixel units by controlling a corresponding plurality of pixel control elements arranged in a matrix form.
Since LCDs cannot emit light by themselves, they require a light source such as a backlight. Backlights used in LCDs may be classified into edge-type backlights and direct-type backlights according to the position of a light source which emits the backlighting light.
In edge-type backlights, one or more light sources are installed at one or more edges of an LCD panel, and light emitted from the light sources is delivered to the LCD panel via a transparent light guide plate (LGP) disposed under the LCD panel. Edge-type backlights can provide very uniform light, can have a long useful life, and are advantageous for making LCDs slimmer. On the other hand, in direct-type backlights, a plurality of light sources are disposed under an LCD panel and they irradiate light directly to the entire surface of the LCD panel rather than relying on a LGP to re-direct light to the back face of the LCD panel. Direct-type backlights can thus ensure high luminance.
Until recently, cold cathode fluorescent lamps (CCFLs) have been generally used as light sources for LCD panels. However, research is being actively conducted to replace CCFLs with light-emitting diodes (LEDs) which have a long useful life, low power consumption, and a lightweight and slim design.